Sulfamethoxazole Trimethoprim Tips from Pharmacists

• You can take sulfamethoxazole trimethoprim with or without food. If it causes an upset stomach, taking it with food might help.

• You should start to feel better after taking the antibiotic for a few days. Continue taking the medicine and finish the full prescribed course even if your symptoms are gone. Skipping doses or stopping treatment too soon can cause your infection to come back and be harder to treat due to antibiotic resistance. Tell your doctor if your symptoms do not improve or get worse.

• Seek immediate medical care if you develop severe bloody or watery diarrhea after taking sulfamethoxazole and trimethoprim. Antimicrobial therapy can put you at risk of a potentially fatal type of diarrhea called Clostridium difficile-associated diarrhea. This can develop up to 2 months or more after finishing antimicrobial treatment.

• If you have diabetes and take oral medications to control blood sugar levels, sulfamethoxazole and trimethoprim can increase the effects of your diabetes medicines, which can lead to low blood sugar. Talk to your doctor about how often you should monitor blood glucose and whether the doses of your diabetes medicines need to be adjusted. 

• Sulfamethoxazole and trimethoprim affect how your body uses folic acid. Use of this antibiotic is not recommended during pregnancy due to an increased risk of birth defects in the unborn baby. Tell your doctor if you are pregnant before starting treatment.